1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16392 Silicone Foams Copyright 2011 General Motors Company All Rights Reserved September 2011 Originating Department: North American Engineering Standards Page 1 of 7 1 Scope Note: Nothing in this standard supercedes applicable laws and regu
2、lations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Material Description. This specification covers a silicone foam material used for sealing various components within a General Motors vehicle. These silicone foam materia
3、ls are recommended for applications where the normal temperature range is -55 C to +200 C. 1.1.1 Material Class. x Class I - Open Cell x Class II - Closed Cell 1.2 Symbols. Not applicable. 1.3 Typical Applications. This material is used as a primary seal for air, dust and automotive fluids where exp
4、osure to high temperatures and low compression set is a factor. Materials can be produced in continuous roll, sheet or cast bun blocks. Products qualified to this specification shall be identified by compression force deflection ranges per ASTM D1056 at 25% compression. 1.3.1 Type 1. This is a low m
5、odulus (soft cellular) foam, which can be easily compressed and used as noise isolation and as an air, dust and fluid seal. 1.3.2 Type 2. This is a medium modulus (medium cellular) foam, which can be easily compressed and used as noise isolation and as an air, dust and fluid seal. 1.3.3 Type 3. This
6、 is a firm modulus (firm cellular) foam, which can be easily compressed and used as noise isolation and as an air, dust and fluid seal. 1.4 Remarks. These materials are considered low-density silicone foams. 2 References Note: Only the latest approved standards are applicable unless otherwise specif
7、ied. 2.1 External Standards/Specifications. ASTM D1056 ISO 3386-1 ISO 815 ISO 6916-1 ISO 1431-1 ISO 23529 ISO 1798 2.2 GM Standards/Specifications. GMW3059 GMW14757 GMW3221 GMW16443 GMW3232 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). Copyright Gen
8、eral Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16392 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 2 of 7 3 Requireme
9、nts 3.1 Requirements on Test Specimens. Reference GMW3221. See Code A. Batch testing will be performed for density, thickness and compression deflection. See Appendix A for Foam Certification Data Form. 3.1.1 Thickness of material shall be tested using 6 0.5 mm product, or as agreed upon between pur
10、chaser and manufacturer. 3.2 Density. Density shall be tested per ASTM D1056. Specific density tolerance range will be supplied within math file or part drawing. Nominal ranges are: x Type 1 (all thicknesses) 152 to 232 kg/m3 x Type 2 (all thicknesses) 300 to 473 kg/m3 x Type 3 (all thicknesses) 336
11、 to 528 kg/m3 3.3 Compression Deflection. Products qualified to this specification shall be tested by compression force deflection ranges per ISO 3386-1 at 25% compression. x Type 1 7 to 41 kPa x Type 2 41 to 97 kPa x Type 3 82 to 138 kPa 3.4 Flammability. Must comply with GMW3232. 3.5 Thickness Tol
12、erance. Thickness tolerance is based on capabilities, and as agreed upon between purchaser and manufacturer. 3.6 Compression Set (ISO 815 Type B). Compression set shall be performed per ASTM D1056 with 50% compression, for 22 h at 100 C. x Type 1 5% maximum x Type 2 10% maximum x Type 3 10% maximum
13、3.7 Tensile Strength (ISO 1798). x Type 1 138 kPa (20 psi) minimum x Types 2 and 3 207 kPa (30 psi) minimum 3.8 Elongation (ISO 1798). x Types 1 and 2 60% minimum x Type 3 45% minimum 3.9 Conical Mandrel Bend Test (ISO 23529). Specimens shall be conditioned for 5 h at -30 C, and then bent 180 degree
14、s around a 70 mm mandrel. Specimens shall show no indication of cracking. 3.10 Water Absorption (ISO 6916-1). Test specimens approximately 12.5 mm (0.5 in) in thickness and 2500 mm2 (4 in2) in area shall be used for this test. Test is performed for 24 h with no vacuum. x Types 1, 2, and 3 5% maximum
15、 3.11 Adhesion Requirement (Adhesive (ADH) Suffix). The adhesive, when applied to foam, must meet requirements of GMW16443 Type I or Type II when tested on production intent substrates. Type will be specified on drawing for each given part. 3.12 Adhesion to Mating Materials (GMW14757). Silicone foam
16、 materials must not stick or leave any residue to mating surfaces such as glass or painted metal when submitted to GMW14757 Method B. 3.13 Ozone Resistance. Expose samples according to ISO 1431-1 using the following condition: 100 10 pphm for 72 h at 40 2 C. Remove samples from chamber and wrap arou
17、nd a 25 mm diameter mandrel. No cracking or other indication of material breakdown is allowed. 3.14 Water Impermeability (Optional). This will only be required for foams which are specified for sealing applications and will be referenced in the global repository of GM approved materials for correspo
18、nding GM Engineering Standards (MATSPC). Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16392 Copyright 2011 General Motors Company All
19、Rights Reserved September 2011 Page 3 of 7 3.14.1 Polycarbonate (PC) plates are used for material comparisons and qualifications. Representative substrates and part dimensions/designs should be tested on appropriate test fixtures to evaluate the material performance in specific applications. 3.14.2
20、Test Fixture. Two 12.5 203 203 mm clear PC plates, spacers of various thickness, and 6.35 38 mm bolts with washers, are to be used. Eight, 7 mm diameter holes are evenly placed around the perimeter of the plastic plates. A 12.5 mm diameter hole is drilled near the top of one plate to allow water to
21、be poured into the fixture. A 3.2 mm diameter hole is drilled near the bottom of the same plate to allow even pressure and permit drainage between test cycles. Non-corrosive metal or plastic spacers may be used to control compression (Figure 1). Figure 1: Water Sealing Test Fixture 3.14.3 Sample Pre
22、paration. A U-shaped gasket, 12.5 mm width, 127 mm wide at open outside ends of U, and 140 mm deep, shall be cut with a special die (see Figure 2). Test at part thickness per blueprint requirements. The material is then sandwiched between the plates and the spacers are placed along the sides of the
23、fixture. Tighten the fasteners all around the fixture to the pattern shown in Figure 1. 3.14.4 As Received Sealability. Condition the samples per GMW3221, Code B. Fill the test fixture with water up to the fill hole. The material must provide a complete water seal for a minimum of 1 h when compresse
24、d 30%. 3.14.5 Aged Sealability. After testing per 3.14.4, the material shall be thermal cycled in the fixture for seven days without water in the fixture. Material shall be thermal cycled in an air-circulating test chamber seven times per the following cycle: x 12 h at 121 C x 12 h at -29 C Note: At
25、 the end of the seven day test, allow the fixture to stabilize per GMW3221, Code B for 1 h. Pour water into the fixture up to the fill hole. Material must maintain a complete water seal for a minimum of 1 h in order to pass these requirements. Copyright General Motors Company Provided by IHS under l
26、icense with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16392 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 4 of 7 Figure 2: Test Sample Dimensions 3.15 Compression Set
27、and Water Seal Tests for Rechargeable Energy Storage Systems. 3.15.1 Foam to be tested shall be 6 mm in thickness. Cut foam to be 75 mm 25 mm. Place foam piece into corrosion resistant compression test plate and compress the foam to 60% of original thickness. Place compression test plate with foam i
28、nto environmental chamber set at 85 C and 95% Relative Humidity (RH). Age the foam for 33 days at the set conditions. Foam must not take a set greater than 10% of its original thickness when measured. 3.15.2 Foam must stabilize according to GMW3221, Code A, for 24 h after environmental exposure outl
29、ined in 3.14.1. Foam must then be centered onto one glass plate so that the length is flush with the 150 mm edge of the glass plate. Put a bead of silicone grease along each foam edge from the bottom to the top of the glass. Obtain four (4) spacers which are 2.4 mm thick. Place each spacer at each c
30、orner of the glass plate, between edge of glass and silicone sealant. Place other glass plate directly over the original glass plate with foam, spacers and silicone grease. Compress the plate down to the spacers. Put a C-clamp at each of the four corners directly over the spacers, and tighten slowly
31、 so as to not break glass. Turn test fixture upright, with clamps in place so that the foam is flush with glass on flat surface. See Figure 3. Figure 3 Test Fixture 3.15.3 Under the test fixture place a white paper. Make up a solution of colored water and fill the test fixture, between the silicone
32、seals, to the top with the colored water. Allow to sit for 24 hours. If white paper is not stained and water level in test fixture has not decreased then foam passes this test. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or
33、networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16392 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 5 of 7 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applica
34、ble laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material spe
35、cification shall be tested for conformity with the requirements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk supplies. A new approval must be received for any changes, e.g., properties, manufacturing process, location
36、 of manufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial release must be completed. It is the responsibility of the supplier to inform the customer in a timely manner, without solicitation, and to include documentation of all modifications of materia
37、ls and/or processes and to apply for a new release. If not otherwise agreed, all release tests shall be repeated and documented by the supplier prior to commencement of delivery of non-conforming bulk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering
38、department and the supplier. 5.4 Initial Source Approval. No shipments shall be made by any supplier until representative initial production samples have been approved by the appropriate Materials Engineering department(s) as meeting the requirements of this specification. 5.5 Material Safety Data S
39、heets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification an
40、d Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.6 All materials s
41、upplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Engineering qualifications of an approved source are required for this standard. Only sources listed in the GM Materials File (i.e., MATSPC) under this standard n
42、umber have been qualified by Engineering as meeting the requirements of this standard. For other GM locations, the responsible engineering group should be contacted to obtain the approved source in that individual country. 7 Notes 7.1 Glossary. MATSPC: Global repository of GM Approved Materials for
43、corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. ADH Adhesive GHS Globally Harmonized System ID/PC Identification/Product Code MSDS Material Safety Data Sheet N/A Not Applicable No. Number PC Polycarbonate RH Relative Humidity SDS Safety Data Sheet Copyright General
44、Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16392 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 6 of 7 8 Coding System
45、This standard shall be referenced in other documents, drawings, etc., as follows: Material per GMW16392 9 Release and Revisions This standard was originated in July 2010. It was first approved by the Global Elastomers Group in August 2011. It was first published in September 2011. Issue Publication
46、Date Description (Organization) 1 SEP 2011 Initial publication. (Global Elastomers Group) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GM
47、W16392 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 7 of 7 Appendix A Data Sheet A1: Foam Certification Data Form Requirement(Section in GMW16392) Method Unit Specified Type Results MeetsDoes Not Meet CommentsDensity (3.2) ASTM D1056 kg/m3 (Type 1) 152 to 232 _ _(Type 2) 300 to 473 _ _(Type 3) 336 to 528 _ _CompressionDeflection (3.3) ISO 3386-1 kPa (Type 1) 7 to 41 _ _(Type 2) 41 to 97 _ _(Type 3) 82 to 138 _ _Flammability (3.4) GMW3232 NBR-SNBR N/A _ _Compression Set (3.6) ASTM D1056 % (Type 1) 5% maximum _ _(Type 2) 10% maximum _ _
